SmogRank / Senegal / Thies / Thiès

Thiès, month by month

Thiès has a measured daily mean on 374 days since 2 August 2025. Its worst month was February 2026, at 56 US AQI (11.7 µg/m³), 1,067th of 2,866 cities on that month's world ranking. Its cleanest was December 2025, at 26 US AQI (4.7 µg/m³).

Every month since 2025

202649 so far266 days measured1,370th of 2,791 in the world
Jan44#1,495Feb56#1,067Mar34#2,528Apr49#1,282May50#998Jun20 daysJul43#1,939Aug41#1,948Sep55#525Oct47#858
2025too few days for a mean (a year needs 256)108 days measured
JanFebMarAprMayJunJulAug15 daysSep9 daysOct44#913Nov46#1,482Dec26#2,755
Each square is a month's mean PM2.5 in US AQI from Thiès's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Thiès marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

3 months
MonthWhy
Jun 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Sep 20259 of 30 days measured; a month needs 21. The others: 21 with under 18 hours of readings or readings that failed our checks.
Aug 202515 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Thiès's worst months

MonthUS AQIDays measuredWorld rank
February 2026 5611.7 µg/m³28 of 281,067thof 2,866
September 2026 5511.5 µg/m³30 of 30525thof 2,981
May 2026 509.0 µg/m³25 of 31998thof 2,874
April 2026 498.8 µg/m³30 of 301,282ndof 2,941
November 2025 468.2 µg/m³29 of 301,482ndof 2,715
January 2026 448.0 µg/m³31 of 311,495thof 2,617

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Thiès's worst days

DayUS AQI
17 Feb 2026 13047.2 µg/m³
10 Jan 2026 12846.6 µg/m³
28 Oct 2025 12344.5 µg/m³
16 Feb 2026 10436.8 µg/m³
26 Jan 2026 9934.9 µg/m³
1 Mar 2026 9130.8 µg/m³
2 Apr 2026 9030.1 µg/m³
9 Jan 2026 8828.7 µg/m³
1 Apr 2026 8728.5 µg/m³
17 Sept 2026 8427.0 µg/m³

Daily means, the highest since 2 Aug 2025; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Thiès, Senegal, 2 Aug 2025 – 11 Oct 2026. Monitor data from AirGradient via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/sn/thies/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Thiès now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 19:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).